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In PQ News
Call of the Month for August 2026 Via the PQ Hotline, a PQ Knowledge funder requested assistance in understanding whether voltage sags of equivalent magnitude (as a percentage of nominal voltage) could be contributing to process trips at one of their customer’s industrial facilities, whereas historically they did not impact operations. The PQK funder provided some basic power quality data. A preliminary review of the information provided suggested voltage variations that resembled step changes. Typically, voltage variations in a process facility may result from I²R losses associated with increased load in the plant or increased load on the utility feed supplying the facility, and these voltage variations are often smooth and continuous. However, based on the limited information provided, the voltage changes appeared more abrupt than would typically be associated with gradual load-related voltage variations. Through follow-up discussions with the inquiring utility, it was reported that the facility is located in an industrial park that participates in a Conservation Voltage Reduction and Optimization (CRVO) program. One potential factor discussed during the inquiry was whether participation in the CRVO program could contribute to the reported behavior. The discussion below reviews what a CRVO program is, how voltage may be actively adjusted, the energy savings that may be realized for different types of three-phase industrial loads, and how reducing nominal voltage may affect single-phase control components in industrial process systems.
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EPRI Industrial PQ Training Videos
As a follow-up to our Industrial Power Quality training classes, we have posted these complementary training videos to help solidify the concepts for both utility members and their customers. The top three are listed here.
Visualizing PQ Drive Parameters for Improved Voltage Sag Ride-Through 
This video demonstrates the voltage sag susceptibility of AC drive systems and how to improve the drive’s robustness through parameter changes.
Understanding PLC Voltage Sag Ride-through: AC and DC Powered Systems
This video demonstrates the differences in voltage sag ride-through between an AC powered PLC system and a DC Powered PLC system.
Power Conditioning to Enhance Control System Voltage Sag Ride-Through: The Constant-Voltage Transformer
This video shows how a CVT can be utilized to harden the voltage sag response of an automated control system.